How was John Proctor a man in as much conflict with himself as he is with the authorities of salem?

John Proctor wanted to be a Puritan at heart. Many people
who participate in organized religions find it easy to partake in the rituals of a given
faith, but to act according to the demands of the soul is a much more difficult, but
honest pursuit.

Proctor was a sinner, he confessed his
great sin and discussed it at length with those who were influenced by his sin. But the
impact of his sin most affected him. When he turned to Abilgail in a lecherous
relationship, he stained his marriage bed from that point forward. Unfortunately,
Puritans failed to focus as much on the grace, forgiveness, and mercy that are offered
in the Bible that they preached as on the sin that they committed. His personal conflict
felt like it had no resolution, there was no method for reparation without
forgiveness. 

The authorities were
similarly unmoved.

When John finally accepts his fateful
punishment for a crime he didn't commit, I think he feels justice was served for the
previous sin of lechery he did commit.